1 /*
2 * Copyright (c) 2009-2011 Atheros Communications Inc.
3 *
4 * Permission to use, copy, modify, and/or distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17 /*
18 * Module for common driver code between ath9k and ath9k_htc
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23
24 #include "common.h"
25
26 MODULE_AUTHOR("Atheros Communications");
27 MODULE_DESCRIPTION("Shared library for Atheros wireless 802.11n LAN cards.");
28 MODULE_LICENSE("Dual BSD/GPL");
29
30 /* Assumes you've already done the endian to CPU conversion */
ath9k_cmn_rx_accept(struct ath_common * common,struct ieee80211_hdr * hdr,struct ieee80211_rx_status * rxs,struct ath_rx_status * rx_stats,bool * decrypt_error,unsigned int rxfilter)31 bool ath9k_cmn_rx_accept(struct ath_common *common,
32 struct ieee80211_hdr *hdr,
33 struct ieee80211_rx_status *rxs,
34 struct ath_rx_status *rx_stats,
35 bool *decrypt_error,
36 unsigned int rxfilter)
37 {
38 struct ath_hw *ah = common->ah;
39 bool is_mc, is_valid_tkip, strip_mic, mic_error;
40 __le16 fc;
41
42 fc = hdr->frame_control;
43
44 is_mc = !!is_multicast_ether_addr(hdr->addr1);
45 is_valid_tkip = rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
46 test_bit(rx_stats->rs_keyix, common->tkip_keymap);
47 strip_mic = is_valid_tkip && ieee80211_is_data(fc) &&
48 ieee80211_has_protected(fc) &&
49 !(rx_stats->rs_status &
50 (ATH9K_RXERR_DECRYPT | ATH9K_RXERR_CRC | ATH9K_RXERR_MIC |
51 ATH9K_RXERR_KEYMISS));
52
53 /*
54 * Key miss events are only relevant for pairwise keys where the
55 * descriptor does contain a valid key index. This has been observed
56 * mostly with CCMP encryption.
57 */
58 if (rx_stats->rs_keyix == ATH9K_RXKEYIX_INVALID ||
59 !test_bit(rx_stats->rs_keyix, common->ccmp_keymap))
60 rx_stats->rs_status &= ~ATH9K_RXERR_KEYMISS;
61
62 mic_error = is_valid_tkip && !ieee80211_is_ctl(fc) &&
63 !ieee80211_has_morefrags(fc) &&
64 !(le16_to_cpu(hdr->seq_ctrl) & IEEE80211_SCTL_FRAG) &&
65 (rx_stats->rs_status & ATH9K_RXERR_MIC);
66
67 /*
68 * The rx_stats->rs_status will not be set until the end of the
69 * chained descriptors so it can be ignored if rs_more is set. The
70 * rs_more will be false at the last element of the chained
71 * descriptors.
72 */
73 if (rx_stats->rs_status != 0) {
74 u8 status_mask;
75
76 if (rx_stats->rs_status & ATH9K_RXERR_CRC) {
77 rxs->flag |= RX_FLAG_FAILED_FCS_CRC;
78 mic_error = false;
79 }
80
81 if ((rx_stats->rs_status & ATH9K_RXERR_DECRYPT) ||
82 (!is_mc && (rx_stats->rs_status & ATH9K_RXERR_KEYMISS))) {
83 *decrypt_error = true;
84 mic_error = false;
85 }
86
87
88 /*
89 * Reject error frames with the exception of
90 * decryption and MIC failures. For monitor mode,
91 * we also ignore the CRC error.
92 */
93 status_mask = ATH9K_RXERR_DECRYPT | ATH9K_RXERR_MIC |
94 ATH9K_RXERR_KEYMISS;
95
96 if (ah->is_monitoring && (rxfilter & FIF_FCSFAIL))
97 status_mask |= ATH9K_RXERR_CRC;
98
99 if (rx_stats->rs_status & ~status_mask)
100 return false;
101 }
102
103 /*
104 * For unicast frames the MIC error bit can have false positives,
105 * so all MIC error reports need to be validated in software.
106 * False negatives are not common, so skip software verification
107 * if the hardware considers the MIC valid.
108 */
109 if (strip_mic)
110 rxs->flag |= RX_FLAG_MMIC_STRIPPED;
111 else if (is_mc && mic_error)
112 rxs->flag |= RX_FLAG_MMIC_ERROR;
113
114 return true;
115 }
116 EXPORT_SYMBOL(ath9k_cmn_rx_accept);
117
ath9k_cmn_rx_skb_postprocess(struct ath_common * common,struct sk_buff * skb,struct ath_rx_status * rx_stats,struct ieee80211_rx_status * rxs,bool decrypt_error)118 void ath9k_cmn_rx_skb_postprocess(struct ath_common *common,
119 struct sk_buff *skb,
120 struct ath_rx_status *rx_stats,
121 struct ieee80211_rx_status *rxs,
122 bool decrypt_error)
123 {
124 struct ath_hw *ah = common->ah;
125 struct ieee80211_hdr *hdr;
126 int hdrlen, padpos, padsize;
127 u8 keyix;
128 __le16 fc;
129
130 /* see if any padding is done by the hw and remove it */
131 hdr = (struct ieee80211_hdr *) skb->data;
132 hdrlen = ieee80211_get_hdrlen_from_skb(skb);
133 fc = hdr->frame_control;
134 padpos = ieee80211_hdrlen(fc);
135
136 /* The MAC header is padded to have 32-bit boundary if the
137 * packet payload is non-zero. The general calculation for
138 * padsize would take into account odd header lengths:
139 * padsize = (4 - padpos % 4) % 4; However, since only
140 * even-length headers are used, padding can only be 0 or 2
141 * bytes and we can optimize this a bit. In addition, we must
142 * not try to remove padding from short control frames that do
143 * not have payload. */
144 padsize = padpos & 3;
145 if (padsize && skb->len>=padpos+padsize+FCS_LEN) {
146 memmove(skb->data + padsize, skb->data, padpos);
147 skb_pull(skb, padsize);
148 }
149
150 keyix = rx_stats->rs_keyix;
151
152 if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error &&
153 ieee80211_has_protected(fc)) {
154 rxs->flag |= RX_FLAG_DECRYPTED;
155 } else if (ieee80211_has_protected(fc)
156 && !decrypt_error && skb->len >= hdrlen + 4) {
157 keyix = skb->data[hdrlen + 3] >> 6;
158
159 if (test_bit(keyix, common->keymap))
160 rxs->flag |= RX_FLAG_DECRYPTED;
161 }
162 if (ah->sw_mgmt_crypto_rx &&
163 (rxs->flag & RX_FLAG_DECRYPTED) &&
164 ieee80211_is_mgmt(fc))
165 /* Use software decrypt for management frames. */
166 rxs->flag &= ~RX_FLAG_DECRYPTED;
167 }
168 EXPORT_SYMBOL(ath9k_cmn_rx_skb_postprocess);
169
ath9k_cmn_process_rate(struct ath_common * common,struct ieee80211_hw * hw,struct ath_rx_status * rx_stats,struct ieee80211_rx_status * rxs)170 int ath9k_cmn_process_rate(struct ath_common *common,
171 struct ieee80211_hw *hw,
172 struct ath_rx_status *rx_stats,
173 struct ieee80211_rx_status *rxs)
174 {
175 struct ieee80211_supported_band *sband;
176 enum ieee80211_band band;
177 unsigned int i = 0;
178 struct ath_hw *ah = common->ah;
179
180 band = ah->curchan->chan->band;
181 sband = hw->wiphy->bands[band];
182
183 if (IS_CHAN_QUARTER_RATE(ah->curchan))
184 rxs->flag |= RX_FLAG_5MHZ;
185 else if (IS_CHAN_HALF_RATE(ah->curchan))
186 rxs->flag |= RX_FLAG_10MHZ;
187
188 if (rx_stats->rs_rate & 0x80) {
189 /* HT rate */
190 rxs->flag |= RX_FLAG_HT;
191 rxs->flag |= rx_stats->flag;
192 rxs->rate_idx = rx_stats->rs_rate & 0x7f;
193 return 0;
194 }
195
196 for (i = 0; i < sband->n_bitrates; i++) {
197 if (sband->bitrates[i].hw_value == rx_stats->rs_rate) {
198 rxs->rate_idx = i;
199 return 0;
200 }
201 if (sband->bitrates[i].hw_value_short == rx_stats->rs_rate) {
202 rxs->flag |= RX_FLAG_SHORTPRE;
203 rxs->rate_idx = i;
204 return 0;
205 }
206 }
207
208 return -EINVAL;
209 }
210 EXPORT_SYMBOL(ath9k_cmn_process_rate);
211
ath9k_cmn_process_rssi(struct ath_common * common,struct ieee80211_hw * hw,struct ath_rx_status * rx_stats,struct ieee80211_rx_status * rxs)212 void ath9k_cmn_process_rssi(struct ath_common *common,
213 struct ieee80211_hw *hw,
214 struct ath_rx_status *rx_stats,
215 struct ieee80211_rx_status *rxs)
216 {
217 struct ath_hw *ah = common->ah;
218 int last_rssi;
219 int rssi = rx_stats->rs_rssi;
220 int i, j;
221
222 /*
223 * RSSI is not available for subframes in an A-MPDU.
224 */
225 if (rx_stats->rs_moreaggr) {
226 rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
227 return;
228 }
229
230 /*
231 * Check if the RSSI for the last subframe in an A-MPDU
232 * or an unaggregated frame is valid.
233 */
234 if (rx_stats->rs_rssi == ATH9K_RSSI_BAD) {
235 rxs->flag |= RX_FLAG_NO_SIGNAL_VAL;
236 return;
237 }
238
239 for (i = 0, j = 0; i < ARRAY_SIZE(rx_stats->rs_rssi_ctl); i++) {
240 s8 rssi;
241
242 if (!(ah->rxchainmask & BIT(i)))
243 continue;
244
245 rssi = rx_stats->rs_rssi_ctl[i];
246 if (rssi != ATH9K_RSSI_BAD) {
247 rxs->chains |= BIT(j);
248 rxs->chain_signal[j] = ah->noise + rssi;
249 }
250 j++;
251 }
252
253 /*
254 * Update Beacon RSSI, this is used by ANI.
255 */
256 if (rx_stats->is_mybeacon &&
257 ((ah->opmode == NL80211_IFTYPE_STATION) ||
258 (ah->opmode == NL80211_IFTYPE_ADHOC))) {
259 ATH_RSSI_LPF(common->last_rssi, rx_stats->rs_rssi);
260 last_rssi = common->last_rssi;
261
262 if (likely(last_rssi != ATH_RSSI_DUMMY_MARKER))
263 rssi = ATH_EP_RND(last_rssi, ATH_RSSI_EP_MULTIPLIER);
264 if (rssi < 0)
265 rssi = 0;
266
267 ah->stats.avgbrssi = rssi;
268 }
269
270 rxs->signal = ah->noise + rx_stats->rs_rssi;
271 }
272 EXPORT_SYMBOL(ath9k_cmn_process_rssi);
273
ath9k_cmn_get_hw_crypto_keytype(struct sk_buff * skb)274 int ath9k_cmn_get_hw_crypto_keytype(struct sk_buff *skb)
275 {
276 struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
277
278 if (tx_info->control.hw_key) {
279 switch (tx_info->control.hw_key->cipher) {
280 case WLAN_CIPHER_SUITE_WEP40:
281 case WLAN_CIPHER_SUITE_WEP104:
282 return ATH9K_KEY_TYPE_WEP;
283 case WLAN_CIPHER_SUITE_TKIP:
284 return ATH9K_KEY_TYPE_TKIP;
285 case WLAN_CIPHER_SUITE_CCMP:
286 return ATH9K_KEY_TYPE_AES;
287 default:
288 break;
289 }
290 }
291
292 return ATH9K_KEY_TYPE_CLEAR;
293 }
294 EXPORT_SYMBOL(ath9k_cmn_get_hw_crypto_keytype);
295
296 /*
297 * Update internal channel flags.
298 */
ath9k_cmn_update_ichannel(struct ath9k_channel * ichan,struct cfg80211_chan_def * chandef)299 static void ath9k_cmn_update_ichannel(struct ath9k_channel *ichan,
300 struct cfg80211_chan_def *chandef)
301 {
302 struct ieee80211_channel *chan = chandef->chan;
303 u16 flags = 0;
304
305 ichan->channel = chan->center_freq;
306 ichan->chan = chan;
307
308 if (chan->band == IEEE80211_BAND_5GHZ)
309 flags |= CHANNEL_5GHZ;
310
311 switch (chandef->width) {
312 case NL80211_CHAN_WIDTH_5:
313 flags |= CHANNEL_QUARTER;
314 break;
315 case NL80211_CHAN_WIDTH_10:
316 flags |= CHANNEL_HALF;
317 break;
318 case NL80211_CHAN_WIDTH_20_NOHT:
319 break;
320 case NL80211_CHAN_WIDTH_20:
321 flags |= CHANNEL_HT;
322 break;
323 case NL80211_CHAN_WIDTH_40:
324 if (chandef->center_freq1 > chandef->chan->center_freq)
325 flags |= CHANNEL_HT40PLUS | CHANNEL_HT;
326 else
327 flags |= CHANNEL_HT40MINUS | CHANNEL_HT;
328 break;
329 default:
330 WARN_ON(1);
331 }
332
333 ichan->channelFlags = flags;
334 }
335
336 /*
337 * Get the internal channel reference.
338 */
ath9k_cmn_get_channel(struct ieee80211_hw * hw,struct ath_hw * ah,struct cfg80211_chan_def * chandef)339 struct ath9k_channel *ath9k_cmn_get_channel(struct ieee80211_hw *hw,
340 struct ath_hw *ah,
341 struct cfg80211_chan_def *chandef)
342 {
343 struct ieee80211_channel *curchan = chandef->chan;
344 struct ath9k_channel *channel;
345
346 channel = &ah->channels[curchan->hw_value];
347 ath9k_cmn_update_ichannel(channel, chandef);
348
349 return channel;
350 }
351 EXPORT_SYMBOL(ath9k_cmn_get_channel);
352
ath9k_cmn_count_streams(unsigned int chainmask,int max)353 int ath9k_cmn_count_streams(unsigned int chainmask, int max)
354 {
355 int streams = 0;
356
357 do {
358 if (++streams == max)
359 break;
360 } while ((chainmask = chainmask & (chainmask - 1)));
361
362 return streams;
363 }
364 EXPORT_SYMBOL(ath9k_cmn_count_streams);
365
ath9k_cmn_update_txpow(struct ath_hw * ah,u16 cur_txpow,u16 new_txpow,u16 * txpower)366 void ath9k_cmn_update_txpow(struct ath_hw *ah, u16 cur_txpow,
367 u16 new_txpow, u16 *txpower)
368 {
369 struct ath_regulatory *reg = ath9k_hw_regulatory(ah);
370
371 if (reg->power_limit != new_txpow)
372 ath9k_hw_set_txpowerlimit(ah, new_txpow, false);
373
374 /* read back in case value is clamped */
375 *txpower = reg->max_power_level;
376 }
377 EXPORT_SYMBOL(ath9k_cmn_update_txpow);
378
ath9k_cmn_init_crypto(struct ath_hw * ah)379 void ath9k_cmn_init_crypto(struct ath_hw *ah)
380 {
381 struct ath_common *common = ath9k_hw_common(ah);
382 int i = 0;
383
384 /* Get the hardware key cache size. */
385 common->keymax = AR_KEYTABLE_SIZE;
386
387 /*
388 * Check whether the separate key cache entries
389 * are required to handle both tx+rx MIC keys.
390 * With split mic keys the number of stations is limited
391 * to 27 otherwise 59.
392 */
393 if (ah->misc_mode & AR_PCU_MIC_NEW_LOC_ENA)
394 common->crypt_caps |= ATH_CRYPT_CAP_MIC_COMBINED;
395
396 /*
397 * Reset the key cache since some parts do not
398 * reset the contents on initial power up.
399 */
400 for (i = 0; i < common->keymax; i++)
401 ath_hw_keyreset(common, (u16) i);
402 }
403 EXPORT_SYMBOL(ath9k_cmn_init_crypto);
404
ath9k_cmn_init(void)405 static int __init ath9k_cmn_init(void)
406 {
407 return 0;
408 }
409 module_init(ath9k_cmn_init);
410
ath9k_cmn_exit(void)411 static void __exit ath9k_cmn_exit(void)
412 {
413 return;
414 }
415 module_exit(ath9k_cmn_exit);
416